This section provides background information related to the present disclosure which is not necessarily prior art.
With increasing environmental awareness and tighter regulations, novel strategies to separate oils from industrial wastewaters, polluted oceanic waters, and oil-spill mixtures, especially in the presence of surfactants, are highly desired. Membrane-based technologies are attractive for demulsification, i.e., the conversion of an emulsion to a free oil-water mixture, because they are relatively energy-efficient and applicable across a wide range of industrial processes. However, separations involving demulsification typically require multiple distinct stages or processes, so that demulsification is followed by either gravity driven separation or skimming for the complete separation of free oil-water mixtures. The present teachings provide improved separation processes for membrane-based technology, which can achieve demulsification among other separations, in a single unit operation. Such separation processes can be gravity driven and are capable of separating all types of oil-water mixtures, with greater than or equal to about 99.9% separation efficiency. Furthermore, the present disclosure provides separations processes that can be actuated and rapidly controlled on-demand.